Electric switch for moving cables with spring-wire trip rod and contacts



Oct. 7, 1969 Ffc. PETERS 3 7 ELECTRIC SWITCH FOR MOVING CABLES WITHSPRING-WIRE TRIP ROD AND CONTACTS Filed Feb. 16, 1968 INVENTOR l8 l7Ham/ck Qaer/rcr 3 75a;

22 A @f/M ATTORNEY United States Patent 3,471,660 ELECTRIC SWITCH FORMOVING CABLES WITH SPRING-WIRE TRIP ROD AND CONTACTS Frederick C.Peters, 2234 Moodie St., Fort William, Ontario, Canada Filed Feb. 16,1968, Ser. No. 706,127 Int. Cl. B65h 25/14; H01h 3/16, 3/00 US. Cl.20061.13 2 Claims ABSTRACT OF THE DISCLOSURE This invention relates tonew and useful improvements in switches for moving cable operateddevices.

Although it is designed primarily for use with ski lift equipment,nevertheless it will be appreciated that it can be utilized in anydevice which uses a moving cable for operating same.

In ski lifts or T-bar lifts, or the like, it is required by law to havesome form of controller adjacent each tower and usually on both theupper and lower runs of the cable so that any movement of the cablebeyond a predetermined amount will trip the switch and cause the deviceto cease operating immediately.

For example, if a cable becomes disengaged from the sheave at a tower,then it is essential that the switch be operated immediately.

Conventional switches include magnetic field operated switches ormicroswitches both of which sulfer from several disadvantages.

The magnetic field type of switch is provided with no flexibility ofoperation due to the fact that the magnetic field is utilized to operatesame. It is therefore usual to incorporate a time delay to prevent minordeflections of the cable from operating the switch.

Microswitches are diflicult to maintain and operate in relatively coldweather and are dilficult to service when on towers which are situatedremotely from the operating center of the ski lift or tow rope.

It is desirable that a switch be provided which can be adjusted as tothe sensitivity of operation and which furthermore can take aconsiderable amount of mechanical abuse Without being damaged.

It is also an essential feature of the switch that it does not resetautomatically but has to be manually set before the cable will againoperate.

The present switch satisfies these requirements inasmuch as it is madefrom spring steel wire, can be adjusted readily, can be used above orbelow a cable, and furthermore can be operated by a turned over T-bar orthe like without damage occurring to the switch.

Furthermore the present switch is economical in manufacture, simple ininstallation and operation, and otherwise well suited to the purpose forwhich it is designed.

With the foregoing considerations in view, and such other objects,purposes or advantages as may become apparent from consideration of thisdisclosure and specification, the present invention consists of theinventive concept exhibited in the method, process, construction,arrangement of parts, or new use of any of the foregoing hereinparticularly exemplified in one or more specific embodiments of suchconcept, reference being had to the accompanying figures in which:

FIGURE 1 is a partial isometric view of the invention per se.

FIGURE 2 is a fragmentary end view of the movable and fixed contactstogether with the indicating rod.

FIGURE 3 is a partially schematic side view showing the relationship ofthe device to one of the sheave pulleys.

FIGURE 4 is a schematic view showing one method of electricalconnections between the motor, the switch, and the indicating device.

In the drawings like characters of reference indicate correspondingparts in the different figures.

Proceeding therefore to describe the invention in detail, referenceshould first be made to FIGURE 1 in which 10 illustrates a strap havingan attaching clamp arrangement 11 at one end thereof within an elongatedslot 12. This enables the strap to be secured to the tower 13 in aconvenient position so that the switch can be located with reference tothe cable 14 as desired.

In FIGURE 3, the strap 10 is shown secured to one of the bolts 15normally holding the bearing for the sheave 16.

On the distal end 17 of the strap, is a further clamping member 18 whichclamps the two legs 19 and 20 of the trip rod collectively designated21. This trip rod includes the substantially vertical anchoring portion19 which is clamped by the aforementioned clamp 18 and then extendsupwardly by means of the U shaped base 22, through an insulator 23 andthence to the anchor portion 19 to which it is spot welded as at 24 forstability.

Formed on the upper end 25 of the anchoring portion 19 is a plurality ofcoils 26 which terminate in the horizontally extending portion 27, saidanchor portion 19, coils 26 and extending portion 27 being madepreferably, from resilient spring steel so that the coiled portion 26permits resilient movement of the extending portion 27 in alldirections.

The anchoring portion 19 extends through an insulator and support 28 asclearly shown and also extending through this insulator and support 28is a fixed control contactor rod 29 which extends upwardly substantiallyparallel to the anchoring portion 19.

The lower end 30 of this rod 29 is connected to a relatively low voltagesource of power indicated in FIG- URE 4 by reference character 31.

Situated on the extending portion 27 of the trip rod 21 and between thedistal end 32 and the spring portion 26, is an insulator and support 33,the portion 27 extending through this insulator and support as clearlyshown.

Also extending through this insulator and support 33 is a movablecontrol contactor rod 34 which is situated substantially parallel to theextending portion 27 but extends rearwardly over the spring portion 26and normally engages the upper end 35 of the fixed control contactor rod29, the resiliency of the coils 26 biasing the rod 34 in contact withrod 35 as shown in FIG. 2.

This movable control contactor rod 34 is also connected to the powersource 31 through a solenoid 36. The solenoid, when the circuit iscomplete as shown in FIGURES 1 and 4, normally pulls the switch 37 intoengagement thus connecting the line power with the motor 38 operatingthe moving cables.

In FIGURE 1, reference character 13 shows the position of the trip rodwith relation to the cable 14. If the cable 14 becomes disengaged fromthe sheave 16 it will drop and strike the trip rod 27 forcing end 32downwardly which automatically moves the inner end 39 of the movablecontrol contactor 34 upwardly, both portions pivotting around the axisof the spring portion 26. This enables the inner end 39 to clear theupper end 35 of the fixed control contactor rod 29 whereupon theresiliency of the spring portion 26 moves it rightwardly 3 with respectto FIG. 2 so that it takes up the position shown in phantom and againstan indicator rod 40 which will hereinafter be described.

As soon as the inner end 39 of rod 34 clears the upper end 35 of rod 29,the circuit of the solenoid 36 is broken so that the switch 37 isdisengaged thus breaking the main circuit to motor 38 and stopping thecable immediately. This cable cannot be restarted until the switch ismanually reset after the fault causing the switch to operate, has beencorrected. The trip rod has to moved downwardly so that the inner end 39clears the upper end 35 of rod 29 whereupon it has to be moved sidewaysagainst the tension of the spring 26 and then the end 32 is movedupwardly so that the inner end 39 once again engages the rod 29 as shownin FIGS. 1 and 2.

It is sometimes desirable that an indicator be supplied adjacent theoperating center for the cable device, so that the operator canascertain exactly Where the fault has occurred.

In this connection I have provided a substantially vertically situatedindicator rod 40 supported in the aforementioned insulator and supportcomponent 23 and extending substantially parallel to the fixed controlcontactor rod 29 but spaced herefrom.

This rod 40 is connected by cable 41 to one side of the source ofelectrical power 31 through an indicating meter 42.

As soon as the switch is operated by cable 14, it contacts the indicatorrod 40 and completes the circuit through the indicator rod to the meter42 and by varying resistors 43, the indicating meter 42 can be designedto indicate exactly which switch has been disengaged thus localizing thefault.

The device can, of course, be reversed so that the trip rod 27 is abovecable 14. The device can also be operated by a T-bar which has becometwisted or otherwise hung up on the cable as a side swiping effect tothe extending end 37 will also cause the switch to disengage, theresiliency of the entire structure preventing damage from occurring tothe switch mechanism.

Various modifications can be made within the scope of the inventiveconcept disclosed. Accordingly, it is intended that What is describedherein should be regarded as illustrative of such concept and not forthe purpose of limiting protection to any particular embodiment thereof,but that only such limitations should be placed upon the scope ofprotection to which the inventor hereof is entitled, as justicedictates.

What is claimed to be the present invention is:

1. In an electric switch of the character described, the combination ofa spring-wire trip rod including a substantially vertical fixed mountingportion and a substantially horizontal feeler portion provided at theupper end of said mounting portion, said feeler portion being -Inovablein vertical and horizontal planes, a substantially horizontal contactarm secured to and movable with said feeler portion, insulating blockmeans provided on said mounting portion, and first and second contactrods supported in horizontally spaced apart relation by said block meansand extending upwardly therefrom with the second contact rod projectingabove said contact arm to a greater extent than the first contact rod,said contact ar-m being normally biased by said spring-Wire trip armagainst a side of said first contact rod opposite from the secondcontact rod, but being movable vertically past the first contact rod andhorizontally against said second contact rod when said feeler portion ofthe trip rod is vertically deflected.

2. The switch as defined in claim 1 wherein said spring-wire trip rodalso includes a coil portion connecting said mounting portion and saidfeeler portion together, said feeler portion extending from said coilportion to one side of the mounting portion, and said contact arm on thefeeler portion extending past the coil portion to the opposite side ofthe mounting portion where said first and second contact rods aredisposed.

References Cited UNITED STATES PATENTS 2,196,784 4/ 1940 Simmons et a1.200--61.l3 X 2,689,890 9/1954 Green 20061.13 2,943,158 6/ 1960 Dubeau.

3,132,466 5/1964 Preisser 200-61.18 X 3,180,950 4/ 1965 JacobsenZOO-61.41 3,254,167 5/1966 Altmann ZOO-61.13 2,912,543 11/1959 Hawkins.

FOREIGN PATENTS 1,137,511 10/1962 Germany.

ROBERT K. SCHAEFER, Primary Examiner R. A. VANDERHYE, Assistant ExaminerUS. 01. X.R. 1200-6141; 166

